Simple gramatical question.

Long story short:
My english teacher says that this sentence is correct:
There aren't very many concerts this month.
While I think it's just
There aren't many concerts this month.
Which one is correct?

Both are grammatically correct. Very is just an adjective and may be omitted or included depending on the speakers intended meaning. It just adds emphasis.

Both, I don't see how very would make it incorrect.

Both are correct. "Very" is not an adjective; it modifies an adjective and is, therefore, an adverb.

I believe your teacher may think that it is wrong because the word "many" implies the word "very", as "many" literally means, "a large number of", while "very" means (in this context), "a high/large degree of."

Essentially, the problem she sees is that you're basically saying, "There are not a large degree of a large number of concerts this month."

Which, when you say it like that sounds pretty terrible.

I'm not saying that either sentence is more grammatically correct than the other, however there is some slight repeating your meaning in the way you say it by using, "Very many," because they both essentially mean "a large amount" in this context.

I believe your teacher may think that it is wrong

Chew's teacher think it's correct. It's Chew who think it isn't.

Both are correct. "Very" is not an adjective; it modifies an adjective and is, therefore, an adverb.

Actually "very" can be used as an adjective or an adverb. It depends on how you use it.

Example: They went to the very bottom of the ocean.

Chew's teacher think it's correct. It's Chew who think it isn't.

Right. I was saying that Chew's teacher may think that Chew's version/sentence is wrong because...

Right. I was saying that Chew's teacher may think that Chew's version/sentence is wrong because...

I think you mixed up which versions Chew and his teacher prefer...

Right. I was saying that Chew's teacher may think that Chew's version/sentence is wrong because...

"Right" what? You're still saying the same as in the post I quoted. Chew's teacher DOESN'T think anything is wrong.
You can't get that from his post. Chew's teacher doesn't think anything's wrong for all we know.
Also, as @CrazyForDex; already mentioned, you're mixing it up and it's actually Chew who thinks it's wrong and it might be because of what you said yeah.

"Right" what? You're still saying the same as in the post I quoted. Chew's teacher DOESN'T think anything is wrong.
You can't get that from his post. Chew's teacher doesn't think anything's wrong for all we know.
Also, as @CrazyForDex; already mentioned, you're mixing it up and it's actually Chew who thinks it's wrong and it might be because of what you said yeah.

Somehow I read that Chew said that their teacher said the first sentence wasn't correct. My bad.

This thread has very many silly mistakes.

This thread has many silly mistakes.

This thread has very many silly mistakes.

This thread has many silly mistakes.

There are very many silly people on southperry.

There are many silly people on southperry.

Conclusion: You are silly

There are very many silly people on southperry.

There are many silly people on southperry.

How many ? Very many.

Very is correct, although if you were writing a paper or any lengthy piece of work, you'd want to avoid using 'very' where possible and use a more descriptive word.

Long story short:
My english teacher says that this sentence is correct:
There aren't very many concerts this month.
While I think it's just
There aren't many concerts this month.
Which one is correct?

Both are wrong. Avoid passive speech.
Rule of thumb: "Don't tell me what it isn't; tell me what it is."

Both are wrong. Avoid passive speech.
Rule of thumb: "Don't tell me what it isn't; tell me what it is."

It is still grammatically correct. Just because it is passive does not mean it is grammatically incorrect.

It is still grammatically correct. Just because it is passive does not mean it is grammatically incorrect.

Are you sure you aren't confusing that with "syntactically correct"?

Are you sure you aren't confusing that with "syntactically correct"?

No.